City Council Speaker Corey Johnson tore into the de Blasio administration for delays in its plan to build thousands of supportive housing apartments for formerly homeless New Yorkers.

Mayor de Blasio promised in 2015 to create 15,000 supportive housing units over 15 years — but so far, only 337 people have actually moved in.

“This pace is unacceptable and is definitely not adequate enough to help the vulnerable New Yorkers that need it,” Johnson said Tuesday. “At the rate we’re going, 15,000 units in 15 years won’t be achievable.”